Introduction
ABS is a new technology in the late 1980s before the rise of applications, has now become the standard configuration of the car in general. When ABS brake may be automatically adjusted to develop the brake pressure of the wheels, preventing the wheels from locking in accordance with movement of the wheel, which is the essence of the traditional process control braking process becomes instantaneous, i.e., with the wheel during braking ground state "hold and die, to die rather than hold", and its purpose is to make wheels for maximum friction with the ground, while avoiding the front and rear road wheels lose steering capability, so the car to get the best braking efficiency.
advantage
shorten the braking distance. ABS obtained can guarantee high braking efficiency of automobiles in rain, snow and muddy road, to prevent side slip tail-flick (and deep snow road except loose sand);
keep the car directional stability during braking;
to maintain steering stability during vehicle braking;
reduce wear of the tire during braking cars. ABS is possible to prevent a dramatic drag marks the tire during braking, tire life improve;
reduce driver fatigue strength (particularly when the automobile braking tension).
Given Antilock Braking System (ABS) having the above advantages, the loading of the system is increased year by year.
development history
ABS technology was developed in 1920 British Horner Moore invented and patented as early as the 1930s, ABS braking system has been in a railway locomotive applications, automotive assembly now ABS is an electrical control apparatus, it is only mechanically-programmed in accordance with the program has already started to perform an action. If the driver did not understand the function of ABS, it is likely to backfire. When pumping the embodiment with ABS brake operation when the vehicle steering capacity lost during braking, the control functions of the vehicle braking state can be prevented. But play a fundamental role is to manipulate the driver, when the driver slammed on the brake pedal in an emergency situation while anxious twist the steering wheel (or lack of experience of many instinctive action panicked who tend to be anxious twist the steering wheel). If the vehicle is not installed locking braking system leading to ABS, overreaction of the steering wheel will not work, then the driver through the steering wheel can not be moved to control the direction of the vehicle; however, if the ABS system allows the driver to control the mounting of the steering wheel, so in the case of panic overreaction of the steering wheel will make it worse. Twisting the steering wheel due to a sudden emergency, they tend to make the car suddenly skidding and accidents.
National Highway Traffic Safety Management Association (NHTSA) tested believes that ESP is installed on the driver's control of the vehicle can be of great help. ESP (electronic control system running smoothly, the English full name of Electronic Stabilty Program) comprising ABS, and the ASR, extending the functions of the two systems, which prevents the wheels from locking and slipping during start braking. ESP continuously checks on the vehicle driving state, it reacts rapidly when an emergency occurs, adjust the pressure of each wheel brake intervention traction engine and by the hydraulic actuator, to reduce the risk of the vehicle skidding. Studies have shown, ESP can reduce traffic accidents by 50%.
Although the ABS does not make the car perfect state of security, but it makes the emergence of the safety car had a very large increase. China's auto industry development plan in the development and application of ABS technology as the first. ABS as a key technology of modern cars, it has a broad development prospects.
At present, the Chinese government has set a mandatory regulatory safety vehicles, GB12676-1999 "automobile brake system structure, performance and test methods", provides first install the electronic control on heavy vehicles and buses type ABS. GB7258-2004 "safe operation of motor vehicles technical conditions" and specifies the models and time that must be installed. Quality requirements must be greater than the total mass 12000kg coach and bus travel is greater than 16000kg allow up to a total mass greater than the trailer 10000kg truck and the total mass greater than the trailer 10000kg must be installed ABS.
China has many units and enterprises engaged in development work ABS, Dongfeng Motor Corporation, Chongqing Highway Research Institute, Beijing Institute of Technology, Tsinghua University, Shanghai Automotive Brake Systems Co., Ltd. and Shandong Heavy Duty Truck Group and so on. Shandong Heavy Duty Truck Group in which the introduction of international advanced technology research has made some progress. Gas ABS brake FKX-ACI-type device is suitable for medium-sized cars Chongqing Institute for Highway has been developed by national technical appraisal, but a variety of adaptive braking situation to be improved. Tsinghua University developed a hydraulic ABS system for light and small cars, Beijing Institute of Technology and Shanghai Automotive Brake Systems Co., Ltd. working on the hydraulic system of the car ABS, have each achieved initial results.
direction
(1) ABS and ASR integrated drive slip control means. ABS for the purpose of preventing wheel lock, ASR is to prevent excessive wheel slip, ABS to relieve the brake, ASR is applied to the brake. Since both technically was closer, and can fully reflect their roles on the low road surface adhesion, so the organically combined.
(2) Dynamic Stability Control VDC (or an electronic stability control (ESP)). VDC mainly to solve the stability problems when the direction of travel of the vehicle steering in the ABS / ASR basis. ABS and electronic suspension control type full (or semi-controlled type), electronic control steering, electronically controlled hydraulic steering, electronic control system in an automatic transmission control function, combine the organic structure to ensure the car in a variety of adverse circumstances when the driving, have good dynamic stability.
(3) ABS / ASR system and the auto-cruise (ACC) integration. Automatic cruise control (ACC) system aims to automatically set a speed limit of the speed in a coasting state, and is capable of traveling ahead of the vehicle in accordance with good automatic braking or acceleration is applied to keep a certain safety distance.
(4) reduced size, reduced weight. In order to improve the safety performance of vehicles, an increase of some devices, the increased weight of the car, fuel economy adversely. Therefore, various devices must be newly added in ensuring safety as possible while reducing the weight. Furthermore, whether large or small car vehicle, the engine installation space is very compact, and therefore, the volume of the ABS controller also requires some as small as possible.
(5) in conjunction with the new generation ABS braking system, the EHB braking hydraulic electronic, electro-mechanical brake the EMB, ABS with faster response, better control, and easier to integrate with other electronic systems. ABS will be integrated automotive chassis systems indispensable to a node.
(6) embedding the electronic brake force distribution system (EBD) in an ABS system, the ABS + EBD system configuration. EBD ABS function is started in the car before the brake pressure regulator to reduce the volume, weight reduction. In order to improve the safety performance of vehicles, an increase of some devices, the increased weight of the car, fuel economy adversely. Therefore, various devices must be newly added in ensuring safety as possible while reducing the weight. Furthermore, whether large or small car vehicle, the engine installation space is very compact, and therefore, the volume of the ABS controller also requires some as small as possible.